Oregon State University is studying how to use bug-on-bug warfare to stop this crop-damaging pest. The insect arrived in the eastern United States in the late 1990s and has since spread to more than 30 states. This non-native bug was found in Portland in 2004 and has since shown up in 13 Oregon counties, including all of the Willamette Valley. The pest has caused major commercial crop damage in many eastern states but so far it has had minimal impact on Northwest crops.

ADVERTISEMENT

The brown marmorated stink bug, or simply the stink bug, is an insect in the family Pentatomidae, and it is native to China, Japan, Korea and Taiwan. It was accidentally introduced into the United States, with the first specimen being collected in September 1998. The brown marmorated stink bug is considered to be an agricultural pest, and by 2010-11 has become a season-long pest in U.S. orchards.

The first documented specimen was collected in Allentown, Pennsylvania, in September 1998. Several Muhlenberg College students were reported to have seen these bugs as early as August of that same year.

Other reports have the brown marmorated stink bug recovered as early as 2000 in New Jersey from a black light trap run by the Rutgers Cooperative Extension in Milford, New Jersey. In 2002, it was again collected in New Jersey from black light traps located in Phillipsburg and Little York and was found on plant material in Stewartsville. It was quickly documented and established in many counties in Pennsylvania, New Jersey, Delaware, Connecticut and New York on the eastern coast of the United States. By 2009, this agricultural pest had reached Maryland, West Virginia, Virginia, Tennessee, North Carolina, Ohio, and Oregon. It has spread to 34 U.S. states.

OSU researchers are looking to a non-pesticide solution to remove this pest: a tiny wasp imported from China. Smaller than a pinhead, the wasp, known as Trissolcus halyomorphae, lays its eggs in the brown marmorated stink bug's eggs.

The potential release of the wasp in the field could still be years away as researchers need to first test its behavior in quarantine to determine if it discriminates between the brown marmorated stink bug's eggs and those of other species. Canada and Mexico must also agree to the wasp's introduction. Any new species could prove as destructive as the old species was.

"The problem with the introduction of biological control organisms is that bugs don't recognize borders like we do - we don’t want to release something that causes more harm than good," said entomologist Peter Shearer, who's leading OSU's stink bug research. "We want to do this right because rarely do we have an ample opportunity to deal with a problem that has the potential to be this bad."

Oregon farmers fear the insect could severely affect crops if its numbers continue to swell. It has already been spotted near some large agricultural operations in Oregon. The bug isn't a picky eater, having shown a taste for more than 100 types of crops, including corn, wine grapes, hazelnuts, pears, apples and sweet cherries.

It leaves behind discolored patches on the food, which is still safe to eat, but the cosmetic blemishes make the products largely worthless in the marketplace.

"It's more of a list of what it doesn't eat than what it does feed on," said Vaughn Walton, an entomologist at OSU. "Identifying where the bug is found is an ongoing effort. Unfortunately, it has been detected in many of Oregon’s major agricultural areas and the populations are increasing. It looks like it could be a problem soon in some areas based on populations we found in 2012."

In the winter, the brown marmorated stink bug seeks shelter indoors, often in attics, garages and dark, moist places. It can be confused with other insects, so the OSU Extension Service has published a two-page guide for the public on how to distinguish it from look-alikes at bit.ly/102dyIw. The document is also in Spanish at bit.ly/S9oHbB.